I had to vote "other" too. I'm a sentimentalist and can't pick just one, but my favorites are the dark rides which I fell in love with as a kid going to DL. Snow White and Peter Pan were both big favorites. I was too scared of Pirates since it scared me terribly as a seven-year-old (it's got a scarier drop at the beginning of the ride in DL). Haunted Mansion is a new favorite.
Up until last year I would have said Peter Pan's Flight: now my favourite ride is Buzz Lightyear. Release that battery Zurg
My neice's is Space Mountain
My Sister's is Splash Mountain
My Nephew's is Stitch's Great Escape
and MBIL just likes to sit under a tree watching the world go by